Field of the Disclosure
This invention relates to a panel, and more particularly a floor panel.
In particular, it relates to a panel of the type wherein this panel comprises a core, an upper side, a lower side and at least two opposite edges; wherein coupling parts are provided on said two opposite edges; wherein said coupling parts have such a configuration that two of such panels can be coupled to each other by means of a downward movement of one of the panels in respect to the other, such that a locking is obtained in the plane of the panels and perpendicular to said edges, as well as perpendicular to the plane of the panels, wherein the coupling parts on said two edges comprise locking parts ensuring said locking in the direction perpendicular to the plane of the panels. Herein, this may relate, for example, to panels are concerned wherein at least one of these locking parts forms part of a flexible part extending along the respective edge and being bendable at least in the plane of the panel, as a result of joining of two of such panels.
Related Art
Panels of this type are known from WO 2008/116623 and WO 2009/033623 and have the feature that they can combine different advantageous characteristics in one and the same panel. In the panels from the above-mentioned patent documents, a flexible part is applied, which is made in one piece with the core. Hereby, a relatively inexpensive production is possible, as such coupling parts can be realized exclusively by means of machining treatments and no separate elements have to be provided in the edge. In that the panels, at two edges, are provided with coupling means allowing to couple such panels to each other by a downward movement, the panels, in the case of floor panels, when also being provided with an appropriate profile on the other edges, can be installed by means of using the user-friendly “angle-push” technique, wherein each newly to install panel is connected to the preceding row of panels by means of a turning technique, and wherein, as a consequence of the downward movement associated therewith, it can be coupled automatically to the preceding panel in the same row, by means of the coupling parts which have said flexible part. By, in this case, making use of a flexible element which is bendable in the plane of the panel and also substantially extends in the plane of the panel, said coupling parts allow to realize a so-called “push-lock” coupling in the core material. However, the core material of the panels of the herein above-mentioned patent documents shows a larger tensioning strength within its plane than perpendicular to its plane, which mostly is the case with wood composite board. This may possibly lead to tearing off of the flexible part from the remainder of the core.
According to the embodiments which are described in WO 2008/116623 and WO 2009/033623, the flexible part consists of a lip which is attached at its distal ends, however, for the rest, at the location of the zone where it is active as a locking part, is entirely made free all around, in order to provide the required flexibility. These known embodiments show the disadvantage that the flexible part made as a lip, in the coupled condition of two panels, can perform a considerable deformation transverse to the plane of the panels. This has as a consequence that, under certain irregular loads, it is impossible to ensure that the panels will not show any height differences at their decorative surfaces. When, for example, in the case of floor panels, a panel is heavily loaded directly next to its coupled edge, for example, by the leg of a heavy piece of furniture, said lip will bend in a plane transverse to the panels, whereby the heaviest-loaded panel possibly will sag deeper into the mostly applied elastically impressible underlying layer than the adjacent panel. Due to the fact that the locking part in the active zone is made entirely free all around, an undefined movement of the flexible part is obtained. In certain cases, for example, when dust particles or small protruding parts of the core material interfere with the movement of the flexible part, this may lead to difficulties when coupling the respective panels.
WO 2004/003314 and WO 2010/142671 also describe panels of the above-mentioned type. Herein, a “push-lock” coupling is realized in the core material of the panels. The panels from these documents comprise a core, an upper side, a lower side and at least two opposite edges, wherein the panels shows pertaining upper edges at said edges; wherein coupling parts are provided on said two opposite edges; wherein these coupling parts have such a configuration that the coupling parts of two such panels can be brought into each other by means of a downward movement of one of the panels in respect to the other, wherein, in the coupled condition of the panels, a locking in the plane of the panels and perpendicular to said edges, as well as perpendicular to the plane of the panels can be obtained, wherein said coupling parts for providing said locking in the plane of the panels and perpendicular to said edges are provided with hook-shaped parts, which, in the coupled condition, show contact surfaces which engage one behind the other. In the example of the mentioned patent documents, the contact surfaces extend in a direction parallel to the respective upper edge.
A disadvantage of the “push-lock” couplings of the state of the art, and then in particular when they are realized in the core material of the panel, is that they require a relatively large force for being assembled and/or that they are cumbersome to be disengaged again. Disengaging the coupling sometimes will be necessary when installing a floor covering consisting of such panels, when, for example, the length of a panel has to be adapted.